Effects of Wing and Nacelle Modifications on Drag and Wake Characteristics of a Bomber-type Airplane Model

Résumé du livre

Summary: An investigation of a model of a large four-engine bomber was conducted in the Langley 19-foot pressure tunnel to determine the effects of several wing and nacelle modification on drag characteristics and air-flow characteristics at the tail. Leading-edge gloves, trailing-edge extensions, and modified nacelle afterbodies were tested individually and in combination. The effects of the various modifications were determined by force tests, tuft observations, and turbulence surveys in the region of the tail. Tests were made with fixed and natural transition on the wing and with propellers operating and propellers off. Most of the tests were conducted at a Reynolds number of approximately 2.6 x 106. The results indicated that application of certain of the modifications provided worth-while improvements in the characteristics of the model. The flow over the wing and flaps was improved, the drag was reduced, and the turbulence in the region of the tail was reduced.